Mattress



FIG. 1 is a perspective view of the front and right side of a mattress showing my new design;

FIG. 2 is another perspective view showing the top cover detached from the mattress;

FIG. 3 is a top plan view thereof;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a left side elevational view thereof; and,

FIG. 6 is a right side elevational view thereof. 

CLAIM The ornamental design for a mattress, as shown and described. 